Rice seed longevity in the context of seed moisture contents and hypoxic conditions in the storage environment

Abstract

Cumulative oxidation of cellular macromolecules during storage reduces seed longevity. This study was undertaken to unravel the physiological and biochemical changes in rice seeds that contribute to deterioration during storage. Rice seeds maintained at three different seed moisture contents (SMC; 10, 12 and 14%) were stored in airtight glass jars. Half of the jars were flushed with nitrogen gas to provide modified oxygen conditions, while the other half were sealed with natural air (21% O2). Seed quality in terms of germination and antioxidant defence mechanisms was monitored after 3 and 6 months of storage at 25°C. The results showed that seeds performed better when stored at low SMC (10 and 12%), whereas the deterioration process accelerated in seeds stored at higher SMC (14%). Coupling high SMC with the availability of oxygen in the storage environment produced a negative effect on seed quality and longevity. Results from the antioxidant analysis showed more activity in seeds stored with oxygen at high SMC (14%) compared to lower SMC stored in modified oxygen conditions. Therefore, it is recommended that storage with low moisture levels (12%) or below (10%) is the best to preserve rice seed quality. However, at higher moisture levels (14%), the availability of oxygen in storage is more harmful to seed lifespan and quality.

The Effects of Oxygen Availability in the Seed Container during Storage on Seed Germination in Tomato, Onion, Cabbage, and Marrow Seeds

“…Earlier studies on the effect of oxygen on longevity have indicated that oxygen plays an effective role in seed germination in barley, peas and broad beans (Roberts and Abdalla, 1968), lettuce (Ibrahim et al, 1983), rye (Barzali et al, 2005), sesame (Ellis and Hong, 2007), onion (Schwember and Bradford, 2011), brassica species (Gonzales-Benito et al, 2011), celery (Groot et al, 2015) and, rice (Tahir et al, 2023) seeds. It appears that the effect of low oxygen was seen to be positive in various type of plant seeds.…”

“…Schwember and Bradford (2011) observed the negative influence of oxygen presence at higher seed moistures in lettuce and onion seeds during artificial ageing. Tahir et al (2023) also mentioned that at higher moisture levels (14%) the availability of oxygen in storage is more harmful to rice seed lifespan than is low seed moisture level (12%). It appears to be that oxygen may have an effect at any seed moisture, but the relative impact may be different (Groot et al, 2015).…”

“…High seed moisture and the natural proportion of oxygen available during storage may accelerate the ageing process of the seeds and negatively affect seed germination as explained by De Vitis et al (2020). The deteriorative effect of oxygen on seed germination was determined to be related to damage to macromolecules (DNA, RNA and proteins) (Sano et al, 2016), ROS (Tahir et al, 2023), and the accumulation of point mutations (Kranner et al, 2011).…”

“…The importance of oxygen on seed storage was first emphasized by Roberts and Abdalla (1968) in rice. More recently however, there are an increasing number of studies in which the deleterious effect of oxygen on longevity has been clearly demonstrated (Barzali et al, 2005;Gonzales-Benito et al, 2011;Schwember and Bradford, 2011;Groot et al, 2012;Groot et al, 2015;Buijs et al, 2020;Pirredda et al, 2020;Prasad et al, 2022;Tahir et al, 2023). The Demir and Kadıoğlu / HortiS (2024) 41( 1):1-5 damaging effect of oxygen on seed germination during storage has been associated with damage to macromolecules (DNA, RNA and proteins) (Sano et al, 2016), ROS enzymes and lipid peroxidation (Tahir et al, 2023), and accumulation of point mutations (Kranner et al, 2011).…”